[pve-devel] [PATCH pve-network v4 10/21] sdn: frr: add daemon status to frr helper

[Gabriel Goller]

From: Stefan Hanreich <s.hanreich at proxmox.com>

Add functions that allow reading and manipulating values in the
/etc/frr/daemons file. We need this for en/disabling daemons depending
on which fabric types are configured. We enable daemons dynamically,
depending on the currently configured fabrics. If a daemon is enabled
but all fabrics using it get deleted, we disable them as well.

The helper works by iterating over the lines of the daemons file from
FRR, parsing the key and checking if the key is managed by the SDN
configuration, then sets it. As a safeguard, keys that can be changed
by SDN have to be explicitly configured in the respective hash of the
Frr module.

Co-authored-by: Gabriel Goller <g.goller at proxmox.com>
Signed-off-by: Stefan Hanreich <s.hanreich at proxmox.com>
---
 src/PVE/Network/SDN.pm         | 18 +++++++++-
 src/PVE/Network/SDN/Fabrics.pm | 15 ++++++++
 src/PVE/Network/SDN/Frr.pm     | 64 ++++++++++++++++++++++++++++++++++
 3 files changed, 96 insertions(+), 1 deletion(-)

diff --git a/src/PVE/Network/SDN.pm b/src/PVE/Network/SDN.pm
index 9fbf14f6a74a..8a3090911a95 100644
--- a/src/PVE/Network/SDN.pm
+++ b/src/PVE/Network/SDN.pm
@@ -331,16 +331,32 @@ sub generate_frr_raw_config {
     return $raw_config;
 }
 
+=head3 get_frr_daemon_status(\%fabric_config)
+
+Returns a hash that indicates which FRR daemons, that are managed by SDN, should
+be enabled / disabled.
+
+=cut
+
+sub get_frr_daemon_status {
+    my ($fabric_config) = @_;
+
+    return PVE::Network::SDN::Fabrics::get_frr_daemon_status($fabric_config);
+}
+
 sub generate_frr_config {
     my ($apply) = @_;
 
     my $running_config = PVE::Network::SDN::running_config();
     my $fabric_config = PVE::Network::SDN::Fabrics::config(1);
 
+    my $daemon_status = PVE::Network::SDN::get_frr_daemon_status($fabric_config);
+    my $needs_restart = PVE::Network::SDN::Frr::set_daemon_status($daemon_status, 1);
+
     my $raw_config = PVE::Network::SDN::generate_frr_raw_config($running_config, $fabric_config);
     PVE::Network::SDN::Frr::write_raw_config($raw_config);
 
-    PVE::Network::SDN::Frr::apply() if $apply;
+    PVE::Network::SDN::Frr::apply($needs_restart) if $apply;
 }
 
 sub generate_dhcp_config {
diff --git a/src/PVE/Network/SDN/Fabrics.pm b/src/PVE/Network/SDN/Fabrics.pm
index e5e3428b278e..94f4e97a2f46 100644
--- a/src/PVE/Network/SDN/Fabrics.pm
+++ b/src/PVE/Network/SDN/Fabrics.pm
@@ -44,6 +44,21 @@ sub write_config {
     cfs_write_file("sdn/fabrics.cfg", $config->to_raw(), 1);
 }
 
+sub get_frr_daemon_status {
+    my ($fabric_config) = @_;
+
+    my $daemon_status = {};
+    my $nodename = PVE::INotify::nodename();
+
+    my $enabled_daemons = $fabric_config->enabled_daemons($nodename);
+
+    for my $daemon (@$enabled_daemons) {
+        $daemon_status->{$daemon} = 1;
+    }
+
+    return $daemon_status;
+}
+
 sub generate_frr_raw_config {
     my ($fabric_config) = @_;
 
diff --git a/src/PVE/Network/SDN/Frr.pm b/src/PVE/Network/SDN/Frr.pm
index 2698928c9b03..62a71e50d9bf 100644
--- a/src/PVE/Network/SDN/Frr.pm
+++ b/src/PVE/Network/SDN/Frr.pm
@@ -109,6 +109,70 @@ sub restart {
     run_command(['systemctl', 'restart', 'frr'], errfunc => $err);
 }
 
+my $SDN_DAEMONS_DEFAULT = {
+    ospfd => 0,
+    fabricd => 0,
+};
+
+=head3 set_daemon_status(\%daemons, $set_default)
+
+Sets the status of all daemons supplied in C<\%daemons>. This only works for
+daemons managed by SDN, as indicated in the C<$SDN_DAEMONS_DEFAULT> constant. If
+a daemon is supplied that isn't managed by SDN then this command will fail. If
+C<$set_default> is set, then additionally all sdn-managed daemons that are
+missing in C<\%daemons> are reset to their default value. It returns whether the
+status of any daemons has changed, which indicates that a restart of the daemon
+is required, rather than only a reload.
+
+=cut
+
+sub set_daemon_status {
+    my ($daemon_status, $set_default) = @_;
+
+    my $daemons_file = "/etc/frr/daemons";
+    die "daemons file does not exist" if !-e $daemons_file;
+
+    for my $daemon (keys %$daemon_status) {
+        die "$daemon is not SDN managed" if !defined $SDN_DAEMONS_DEFAULT->{$daemon};
+    }
+
+    if ($set_default) {
+        for my $daemon (keys %$SDN_DAEMONS_DEFAULT) {
+            $daemon_status->{$daemon} = $SDN_DAEMONS_DEFAULT->{$daemon}
+                if !defined($daemon_status->{$daemon});
+        }
+    }
+
+    my $old_config = PVE::Tools::file_get_contents($daemons_file);
+    my $new_config = "";
+
+    my $changed = 0;
+
+    my @lines = split(/\n/, $old_config);
+
+    for my $line (@lines) {
+        if ($line =~ m/^([a-z_]+)=/) {
+            my $key = $1;
+            my $status = $daemon_status->{$key};
+
+            if (defined $status) {
+                my $value = $status ? "yes" : "no";
+                my $new_line = "$key=$value";
+
+                $changed = 1 if $new_line ne $line;
+
+                $line = $new_line;
+            }
+        }
+
+        $new_config .= "$line\n";
+    }
+
+    PVE::Tools::file_set_contents($daemons_file, $new_config);
+
+    return $changed;
+}
+
 =head3 to_raw_config(\%frr_config)
 
 Converts a given C<\%frr_config> to the raw config format.
-- 
2.39.5